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How to solve the problem of frequency drop during microphone use?


  What are the causes of microphone frequency drop?There is no problem with the microphone when there are few people in the performance, and there is a frequency cut when there are many people. Our friends who often perform will encounter such problems. The microphone has always been used well in the rehearsal process, but as soon as the audience comes, the phenomenon of frequency cut-off occurs at the critical time of the formal performance.

  Why does this problem occur?It turns out that the transmission of UHF band is generally dominated by direct radiation, but some signals can reach the receiver by penetrating obstacles and refraction. However, when we perform, especially when performing outdoors, we are surrounded by empty venues, so refraction cannot exist.

At the same time, during a formal performance, there will inevitably be a large audience. If the main console is placed in the golden listening position of the audience, the antenna of the receiver may be blocked by the audience. Although our UHF signal can penetrate part of the audience's body to the receiving antenna, the more objects the signal penetrates, the greater the attenuation will inevitably be. When it reaches the antenna, its power may not be enough to open the receiver's sensitivity "gate", which causes the phenomenon of frequency interruption.

  How to solve the problem of microphone frequency drop?Microphone out of the frequency of the solution has the following:

1. When using a single set of wireless microphones, try to choose a microphone host with sensitivity adjustment function;

If a single set of wireless microphone is used and the microphone has sensitivity adjustment function: at this time, we will first adjust the sensitivity of the receiver to the maximum. if there is still a frequency cut-off phenomenon, we can place the microphone higher than the audience (preferably at the stage entrance); Or extend the antenna of the microphone to the outside, but at this time we need an auxiliary device-antenna amplifier, because the extension of the antenna cable will bring some gain loss, and the antenna amplifier can make up for the gain loss caused by the coaxial cable.

2. When using multiple sets of wireless microphones

If you use multiple sets of wireless microphones: at this time, it is impossible for us to place so many wireless microphones on the stage, and it seems not very realistic to pull many antennas above the console. However, in the end we still have a way to solve this kind of problem. We can add another device-wireless microphone antenna distributor. This device can make several sets of microphones share one antenna through the internal matching circuit, and then cooperate with the antenna amplifier. At this time, we can find two higher microphone brackets to support the antenna amplifier, thus we can solve the problem of stable reception when multiple sets of microphones are used at the same time.

3. When performing on larger occasions

Because the microphone user moves in a large space, the transmission distance of the wireless microphone cannot meet the needs. When we do large-scale concerts in the stadium, we often have to build a large stage and several floors of light stands, all of which are not conducive to the use of wireless microphones. As we all know, the standard transmission power of wireless microphones is 10mW. Due to the transmission in the air and the barrier and absorption of some substances, the propagation distance is very limited, and the sensitivity of the receiver will also have a certain impact on the receiving distance. The transmission distance of the general wireless microphone is 50-120 meters. If the environment used has strong electromagnetic interference or electromagnetic shielding, the transmission distance may not exceed 50 meters.

To sum up, wireless microphones will still be tested in large-scale performances. However, if the antenna distributor and antenna amplifier are used together, the problem of disconnection can be avoided to a large extent. If we use wireless microphones within four sets, we only need one antenna distributor and two antenna amplifiers to form a combination. Only we need to use coaxial cable to pull the antenna amplifier as close as possible to the edge of the stage. It would be great if it could be fixed on the lamp stand of the stage.

This condescending antenna installation method can ensure that the transmitted signal is not blocked in most cases, thereby ensuring a stable receiving effect. Using this method, we can also make some trade-offs. If we want to ensure strong receiving stability, the distance between the two antenna amplifiers should be kept between 50M-100M as much as possible, because we can use the automatic selection function of the microphone.

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